1. Field
The following description relates to a bidirectional optical transceiver module, and more particularly, to a bidirectional optical transceiver module with a temperature control function.
2. Description of the Related Art
Passive optical network (PON)-based bidirectional optical transceiver modules have recently been manufactured with a single-fiber type bidirectional optical subassembly (BOSA) instead of with a dual-fiber type BOSA to reduce the optical fiber installation cost or line rental fee.
FIG. 1 illustrates a bidirectional optical transceiver module according to a related art. Referring to FIG. 1, the bidirectional optical transceiver module 10 includes a TO-Can type optical transmitter module 21 and a TO-Can type optical receiver module 31 which are arranged with respect to an optical filter 41.
The optical transmitter module 21 and the optical receiver module 31 are arranged and fixed to a housing 51 by a laser welder. The optical filter 41 is provided in the housing 51. The optical filter 41 transmits light from the optical transmitter module 21 to an optical fiber 62 inserted into a ferrule 61, and reflects light, which is input through the optical fiber 62, to the optical receiver module 31. The optical transmitter module 21 is equipped with a laser diode and a collimating lens 24 which are built in a TO-Can package 22. The optical receiver module 31 is equipped with a photodiode 33 and a focusing lens 34 which are built in a TO-Can package 32.
For an electro-absorptive laser (EML) for high-speed (e.g., 10 Gbps or more) long-distance transmission or a wavelength division multiplexing (WDM) which lays stress on stable wavelengths, the optical transmitter module 21 requires temperature control. For this purpose, the optical transmitter module 21 may be equipped with a cooler for temperature control. In this case, the optical transmitter module 21 is securely fixed to a heat sink or an optical transceiver case to radiate heat from the cooler.
In this case, the housing 51 and the optical receiver module 31 are not fixed to the heat sink or the optical transceiver case but are hung on the optical transmitter module 21. This may cause a coupled portion between the optical transmitter module 21 and the housing 51 or between the housing 51 and the optical receiver module 31 to be vulnerable to external impact or vibration. Accordingly, in considering processes such as optical alignment and laser welding, the conventional bidirectional optical transceiver module disadvantageously grows large and complicated.